Silver dye bleach process using chelated dyes



DEFENSIVE PUBLICATION UNITED STATES PATENT OFFICE Published at the request of the applicant or owner in accordance with the Notice of Dec. 16, 1969, 869 0.6. 687. The

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Defensive Publication applications have not been examined as to the merits of alleged invention. The Patent Ofilce makes no assertion as to the novelty of the disclosed subject matter.

PUBLISHED DECEMBER 1, 1970 T881,012 SILVER DYE BLEACH PROCESS USING CHELATED DYES John Williams and Robert T. Claunch, Pittsford, N.Y. (both of 1669 Lake Ave., Rochester, N.Y. 14650) Filed June 11, 1970, Ser. No. 45,461 Int. Cl. G03c 1/76 US. C]. 9673 1 Sheet Drawing. 29 Pages Specification A photographic silver-dye-bleach element of improved speed contains in one or more emulsion layers an azo dye which during image exposure absorbs radiation of diiferent wavelength from that of the sensitizing dye of the particular emulsion. In this Way the speed loss inherent in conventional silver-dye-bleach products which contain dyes that adsorb light in the same range as the emulsion, is avoided. These azo dyes form a metal complex, e.g., a chelate, of different hue from that of the non-metallized dye and bleach in the presence of developed silver. Therefore, after exposure the dyes are complexed with a metal such as Co, Ni, Cu, Cr or Pb during or after black and white processing to yield a dye which is complementary in color to the sensitivity of its emulsion layer. The metal complexes also provide improved dye stability and extinction. The resultant image is positive, as the dye and silver associated with the image are destroyed in a bleach bath. Examples of suitable azo dyes include: S-acetamido- 1-hydroxy-2-(8 quinolylazo)-5,7-naphthalene disulfonic acid disodium salt; 8-amino-2- (4-benzotriazolylazo)-1-hydroxy-5,7-naphthalene disulfonic acid disodium salt; and 1-hydr0xy-4-(8 quinolyl)-2-[4 (2.4 di-tert-amylphenoxy)-n-butyl]naphthamide. I

1970 J. WILLIAMS ET T33L012 SILVER DYE BLEACH PROCESS USING CHELATED DYES' Filed June 11, 1970 /7 ExPO'sURE 1 BLUE 1 GREEN REO 5 aLUE-sE/vs/r/vE AgX EMULs/O/v I U/vcHELA TED OYE 7 l4 YELLOW F/L rER LA YER /3 OREE/vsEA/s/r/vE AgX EMULs/O/v UNCHELATED YELLOW OYE {RED-SENSITIVE AgX EMULSION UA/CHELATED MAGENTA OYE SUPPORT ELEMENT AFTER PROCESS/N6" I /5" YELLOW CHELATEO YE /4 cOLORLEss INTERLAYER /3' MAGENTA CHELA rEO OYE /2 Om/v CHELATED OYE sUPPORr BL UE-SENS/T/VE EMU s/O/v GREEN- SENS/77250 EMULSION r I l 2/ I L k 7 REDSEN8/T/ZED v EMULSION aOO 400 500 600 700 WAVE LENGTHlm/u) JOHN WILLIAMS v A rrOR/v Y 

